A bomb on a ferry in the southern Philippines has injured at least 30 people, including nine children.

Passengers were boarding the Dona Ramona at Lamitan on the island of Basilan were the blast occurred.

The island's military commander said a homemade device designed "to sow terror" had been left near gas cylinders in the ferry's canteen.

Basilan is the base for the Abu Sayyaf Muslim insurgents, and the island has a history of political violence.

Earlier in August, 26 people were injured by two explosions in the port city of Zamboanga, an attack blamed on Abu Sayyaf, a group which has been linked to al-Qaeda.

The Dona Ramona had been due to sail to Zamboanga.

Flown to hospital

Six people, including a soldier, suffered severe burns when the bomb exploded at about 0730 on Sunday (2330GMT Saturday).

When the explosion went off, it started a small fire on the steel-hulled vessel.

"This could be a concealed explosive device without metallic parts. The apparent intention was to injure and scare people," said Brigadier-General Raymundo Ferrer, Basilan's army commander, as he inspected the damage.

"We have evacuated the ship and sent the wounded people to nearby hospitals."

A military helicopter flew the most severely wounded to Zamboanga.

Brig-Gen Ferrer added that no group had so far claimed responsibility for the blast.